How to update head unit MAX M140-BTX. 
Instructions how to update MAX M140-BTX with serial number higher than MAXM140BTX220601100
Check for which software version installed in unit.
1.	Select radio as the source.
2.	Press buttons 2, 5, and 3 with about 3 seconds of pressing each.
3.	The software version will be shown in the display. (52751911111)
Latest version available is 52751911114
 
MCU update version 52751911114 use attached cdp-file: 52751911.cdp
1.	Download the latest MCU software for your stereo via the links below.
2.	Use an empty USB drive and save the software file to the USB drive.
3.	Start the stereo with the Power button.
4.	Select radio as the source.
5.	Insert the USB drive into the car stereo’s USB port.
6.	Press buttons 2, 5, and 4 with about 3 seconds of pressing each.
7.	Wait for the text UPDATE to appear on the display. When the text UPDATE appears on the screen, the stereo will perform the program update.
8.	When the update is complete, the text UPDATE will disappear from the display and the stereo will turn off.
9.	Remove the USB drive.
10.	Start the stereo with the Power button
11.	Reset the device by pressing the button in the hole marked RST (Reset). This can be done, for example, with a paper clip.
12.	The update is now complete.
13.	Start the stereo with the Power button.
14.	After the update, the stereo is reset to factory settings, so any sound settings will need to be redone.
 
DSP update use attached cdp-file: dsp.cdp
1.	Download the latest DSP software for your stereo via the links below.
2.	Use an empty USB drive and save the software file to the USB drive together with one music track in MP3 format. (The MP3 track is important for this DSP update to work properly.)
3.	Start the stereo with the Power button.
4.	Select radio as the source.
5.	Insert the USB drive into the car stereo’s USB port.
6.	Press buttons 2, 5, and 1 with about 3 seconds of pressing each.
7.	Wait for the text DSP UPDATING to appear on the display. When the text DSP UPDATING appears on the screen, the stereo will perform the program update.
8.	When the update is complete, the text DSP UPDATING will disappear from the display and the stereo will turn off.
9.	Remove the USB drive.
10.	Start the stereo with the Power button
11.	Reset the device by pressing the button in the hole marked RST (Reset). This can be done, for example, with a paper clip.
12.	The update is now complete.
13.	Start the stereo with the Power button.
14.	After the update, the stereo is reset to factory settings, so any sound settings will need to be redone.
